PORT CANAVERAL, Fla. — Royal Caribbean is now requiring cruise guests to take a COVID-19 test before leaving for their trip, regardless of whether they're vaccinated.

The cruise line made the announcement last week, for cruises running between now and December 31. 

The company is requiring that all guests 2 years of age and older, on cruises that are five nights or longer, must get a COVID-19 test with an accredited provider, no more than three days before arriving at the terminal to get on board. Guests will need to show the negative test results in order to sail. 

Guests who are unvaccinated will still need to take part in COVID tests at the port, in addition to the pre-cruise test.

Guests on cruises that are four nights long or less who are fully-vaccinated can show their vaccination documentation before boarding, instead of getting a COVID test.

Full details are on Royal Caribbean's "Getting Ready to Sail" section of its website.

The decision comes in the wake of a Royal Caribbean cruise last week where six people on board Royal Caribbean's Adventure of the Seas tested positive for COVID-19. Four of them were vaccinated. Two were minors. 

All of the guests were quarantined, according to RCL, and all people who came in close contact were traced and tested. The six patients were flown back to the U.S. on private transportation at RCL's expense. 

Royal Caribbean's first regular cruise from Port Canaveral will be Sunday, on board Allure of the Seas. Guests will need to have negative COVID tests to present for that cruise.

The passengers will also have to have something else in order to board Allure of the Seas — proof of vaccination.

The ship is sailing to St. Thomas in the U.S. Virgin Islands. However, the USVI government has mandated that all passengers 12 years and older must be fully vaccinated in order for the cruise ships to even stop at St. Thomas, even if the unvaccinated guests do not disembark. Those guests must have proof that they are fully vaccinated at the port before they board the ship.

The CDC says the U.S. Virgin Islands is a very high risk destination for COVID-19, due to the high number of cases. The agency says people should be fully vaccinated when visiting, and should wear a mask and follow social distancing protocols. More information is on the CDC website.

Reporter Will Robinson-Smith contributed to this story.